Ion mobility spectrometry and ion mobility spectrometers are well established. The ion mobility spectrometer (IMS) device may include a sample inlet, ionization region, shutter grid, drift region, and ionized particle detector. Ion mobility spectrometers separate ions according to mobilities through a drift gas in a constant electric field. The ionization and separation processes occur under a wide range of pressures, for example, atmospheric pressure and a wide range of temperatures and drift gas composition. In operation, a uniform or linear field, for example, 200 V/cm, is applied across the drift region and the various ions upon release by the shutter grid or other means are allowed to drift through the drift region toward the ionized particle detector. After release by the shutter grid, the ions of a particular mobility, K0, are located at a particular location in the drift region at each instant of time. The ion detector provides a signal indicative of the number of ions arriving at a collector plate and the time lapse from the time the shutter grid was pulsed open to the time the ions arrive at the collector is an indication of the mobility of the ions collected. For additional details regarding ion mobility spectrometry, U.S. Pat. No. 4,855,595 has been incorporated herein in its entirety by reference. The present inventors have recognized the importance of improved systems and methods which utilize IMS to separate particles, for example, smaller particles of about 0.001 microns.